tankmates

Tankmates are the other aquatic animals kept in the same aquarium with one or more focal species. They can include fish, shrimp, snails, and other invertebrates, and, in marine setups, a wider range of compatible species. The aim is a stable, peaceful community that shares the same environment.

Key considerations include tank size and layout, the temperament and adult size of each species, and matching water parameters such as temperature, pH, and hardness. Diet compatibility is also important, as some fish require carnivorous, herbivorous, or omnivorous diets. The presence of hiding places, plants, and territories helps reduce aggression. Introductions should be gradual, and new arrivals should be quarantined when possible to prevent disease.

Commonly compatible groups include peaceful schooling fish such as neon and cardinal tetras, ember rasboras, harlequin rasboras, and danios; bottom-dwellers such as Corydoras and small loaches; and small, peaceful invertebrates like certain shrimp and snails. In planted aquariums, these species often coexist well if adult sizes and temperaments are considered. Be aware that shrimp and small fish can sometimes be viewed as food by larger or more aggressive tankmates.

Incompatible groupings include highly aggressive or territorial species such as some large cichlids or large gouramis; fin-nippers such as tiger barbs; and predatory fish that will hunt smaller tankmates. Species with very different water or salinity requirements should not be kept together.

In saltwater or brackish setups, compatibility follows different rules and requires careful species-specific research. Regular monitoring and maintenance remain essential to a successful community tank.